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agent-customization

**WORKFLOW SKILL** — Create, update, review, fix, or debug VS Code agent customization files (.instructions.md, .prompt.md, .agent.md, SKILL.md, copilot-instructions.md, AGENTS.md). USE FOR: saving coding preferences; troubleshooting why instructions/skills/agents are ignored or not invoked; configuring applyTo patterns; defining tool restrictions; creating custom agent modes or specialized workflows; packaging domain knowledge; fixing YAML frontmatter syntax. DO NOT USE FOR: general coding questions (use default agent); runtime debugging or error diagnosis; MCP server configuration (use MCP docs directly); VS Code extension development. INVOKES: file system tools (read/write customization files), ask-questions tool (interview user for requirements), subagents for codebase exploration. FOR SINGLE OPERATIONS: For quick YAML frontmatter fixes or creating a single file from a known pattern, edit the file directly — no skill needed.

72

Quality

89%

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SKILL.md
Quality
Evals
Security

Quality

Content

86%Weight 40%Scale 1-5

Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.

The body is a well-structured overview: token-efficient tables, a sound creation workflow with validation, edge-case decision rules, and a clean one-level reference layout. The main weakness is that file-creation guidance leans on the references for concrete templates, leaving a few minor gaps in the main workflow.

Suggestions

In 'Step 3: Create the File', inline one minimal frontmatter template (e.g., a two-line SKILL.md header) so the most common case is executable without loading a reference file.

Strengthen 'Step 4: Validate' with an error-recovery branch (e.g., 'if frontmatter fails to parse, check for unescaped colons/tabs and re-check') to close the feedback loop.

Add a line in the Quick Reference section covering common natural-language triggers (slash commands, chat modes) to align the body's trigger guidance with the description's USE FOR list.

DimensionReasoningScore

Conciseness

Lean and efficient: dense decision-flow and location tables, no concept explanations Claude already knows, no padding — every section (Decision Flow, Quick Reference, Creation Process, Edge Cases, Common Pitfalls) adds non-obvious discriminating knowledge. Matches the 'every token earns its place' anchor.

5 / 5

Actionability

Mostly concrete, executable guidance: exact paths (.github/instructions/, {{VSCODE_USER_PROMPTS_FOLDER}}/), specific rules ('Always quote descriptions that contain colons', avoid applyTo: "**"), and per-primitive reference links. Not 5: step 3 ('Include required frontmatter as needed', 'Add the body content following the templates') is loose and defers all templates/examples to references without inline minimal examples; not 3: what is written is specific and directly actionable.

4 / 5

Workflow Clarity

Clear four-step sequence (Determine Scope → Choose Primitive → Create File → Validate) with an explicit validation step (correct location, YAML frontmatter syntax, description present). Not 5: validation is a light checklist without feedback-loop detail (what to do on failure, how to verify syntax mechanically); not 3: the sequence and checkpoints are explicitly present, and no destructive/batch operations apply the cap.

4 / 5

Progressive Disclosure

Clear overview in SKILL.md with well-signaled, one-level-deep references: all six linked files (agent-instructions.md, instructions.md, prompts.md, hooks.md, agents.md, skills.md) exist, are organized per primitive in a navigation table, and contain no further nested references. Matches the 'clear overview with well-signaled one-level-deep references' anchor.

5 / 5

Total

18

/

20

Passed

Description

92%Weight 40%Scale 1-5

Based on the skill's description, can an agent find and select it at the right time? Clear, specific descriptions lead to better discovery.

A strong description: concrete and comprehensive on capabilities, with explicit USE FOR / DO NOT USE FOR trigger guidance and file extensions. The only gap is a handful of natural synonyms users might phrase differently (slash commands, chat modes).

DimensionReasoningScore

Specificity

Lists multiple concrete actions ("Create, update, review, fix, or debug", "configuring applyTo patterns", "defining tool restrictions", "fixing YAML frontmatter syntax") with comprehensive coverage of the domain and its file types (.instructions.md, .prompt.md, .agent.md, SKILL.md, copilot-instructions.md, AGENTS.md). Fits the anchor 'Lists multiple specific concrete actions; comprehensive coverage' — the score-4 anchor ('minor gaps in coverage') does not apply since every customization file type and operation is named.

5 / 5

Completeness

Explicitly answers both 'what' (create/update/review/fix/debug VS Code agent customization files) and 'when' (USE FOR list with concrete triggers, plus DO NOT USE FOR exclusions and a single-operation carve-out). Matches the anchor 'Clearly and explicitly answers both what AND when with concrete trigger phrases'.

5 / 5

Trigger Term Quality

Good keyword coverage with natural phrases users would say ("saving coding preferences", "troubleshooting why instructions/skills/agents are ignored or not invoked") and file extensions. Not 5: a few natural user terms are missing (e.g., 'slash commands', 'chat modes', 'custom instructions'); not 3: coverage clearly exceeds 'some relevant keywords'.

4 / 5

Distinctiveness Conflict Risk

Clear niche (VS Code agent customization files) with distinct triggers, and the DO NOT USE FOR list (general coding questions, MCP server configuration, extension development) actively reduces conflict risk. Minimal overlap risk with unrelated skills.

5 / 5

Total

19

/

20

Passed

Validation

93%

Checks the skill against the spec for correct structure and formatting. All validation checks must pass before discovery and implementation can be scored.

Validation — 15 / 16 Passed

Validation for skill structure

CriteriaDescriptionResult

referenced_paths_exist

Referenced path issues: 1 missing

Warning

Total

15

/

16

Passed

Repository
posit-dev/positron
Reviewed

Table of Contents

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